US5679266A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for assembly of printed circuit boards with ultrafine pitch components using organic solderability preservatives
Assignee: Texas Instruments Inc
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Filing: 1996-01-16
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Granted: 1997-10-21
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Expires: 2016-01-16
Abstract
Abstract A method of assembling a printed circuit (PC) boards with ultrafine pitch components. The method comprises: attaching a coarse pitch components on the PC board; applying solvent to the thermal pads of the ultrafine pitch components; mounting a die-attach film on the thermal pads; curing the die-attach film; applying solvent to the die-attach film; forming component leads for the ultrafine pitch components; aligning the ultrafine pitch components to the solder pads; attaching the component leads to the solder pads and the ultrafine pitch components to the thermal pads. Other devices, systems and methods are also disclosed.
Inventors
- 👤 Vijay S. Darekar
- 👤 Chris N. Thornton
- 👤 John W. Krueger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:29
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3415; H05K3/22; H05K3/28; H05K3/282; H05K3/303; H05K3/305; H05K1/00; H05K1/02; H05K1/0201; H05K1/0203; H05K1/0204; H05K1/0206; H05K2201/00; H05K2201/09; H05K2201/09209; H05K2201/09654; H05K2201/09781; H05K2201/10; H05K2201/10613; H05K2201/10621; H05K2201/10681; H05K2201/10954; H05K2201/10969; H05K2203/00; H05K2203/01; H05K2203/0195; H05K2203/12; H05K2203/122; H05K2203/124; H05K2203/14; H05K2203/1476; H05K2203/15; H05K2203/1572; H05K3/3421; Y; Y02; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
86 words
A method of assembling coarse pitch components and ultrafine pitch components on a printed circuit (PC) board, said method comprising: providing a PC board having ultrafine pitch components with thermal pads and solder pads; attaching coarse pitch components on said PC board; mounting a die-attach film on said thermal pads; curing said die-attach film; applying solvent to said die-attach film; forming component leads on said ultrafine pitch components; aligning said component leads to said solder pads; and mounting said ultrafine pitch components to said thermal pads.
Claim 2
Independent Claim
86 words
A method of assembling coarse pitch components and ultrafine pitch components on a printed circuit (PC) board, said method comprising: providing a PC board having ultrafine pitch components with thermal pads and solder pads; attaching coarse pitch components on said PC board; mounting a die-attach film on said thermal pads; curing said die-attach film; applying solvent to said die-attach film; forming component leads on said ultrafine pitch components; aligning said component leads to said solder pads; and mounting said ultrafine pitch components to said thermal pads.
Claim 3
Dependent Claim
67 words
The method of claim 1, wherein said attaching coarse pitch components includes: paste printing a frontside of said PC board; dispensing glue on said frontside of said PC board; placing coarse pitch components on said frontside of said PC board; reflowing said frontside of said PC board; and repeating said paste printing, said dispensing said placing and said reflowing steps for a backside of said PC board.
Claim 4
Dependent Claim
33 words
The method of claim 1, further including: positioning said PC board in a solder dispensing machine; and heating said PC board in said solder dispensing machine; and applying flux to said solder pads.
Claim 5
Dependent Claim
24 words
The method of claim 1, wherein said curing said die-attach film consists of curing at 190 degrees Fahrenheit (88 degrees Celsius) for 5 minutes.
Claim 6
Dependent Claim
19 words
The method of claim 1, wherein said method further includes pressing said ultrafine pitch components with a heated thermode.
Claim 7
Independent Claim
142 words
A method of assembling coarse pitch components and ultrafine pitch components on a printed circuit (PC) board, said method comprising: providing a PC board having ultrafine pitch components with thermal pads and solder pads; paste printing a frontside of said PC board; dispensing glue on said frontside of said PC board; placing coarse pitch components on said frontside of said PC board; reflowing said frontside of said PC board; repeating said paste printing, said dispensing, said placing, and said reflowing for a backside of said PC board; applying solvent to said thermal pads of said ultrafine pitch components; mounting a die-attach film on said thermal pads; curing said die-attach film; applying solvent to said die-attach film; forming component leads on said ultrafine pitch components; aligning said component leads to said solder pads; and mounting said ultrafine pitch components to said thermal pads.
Claim 8
Independent Claim
142 words
A method of assembling coarse pitch components and ultrafine pitch components on a printed circuit (PC) board, said method comprising: providing a PC board having ultrafine pitch components with thermal pads and solder pads; paste printing a frontside of said PC board; dispensing glue on said frontside of said PC board; placing coarse pitch components on said frontside of said PC board; reflowing said frontside of said PC board; repeating said paste printing, said dispensing, said placing, and said reflowing for a backside of said PC board; applying solvent to said thermal pads of said ultrafine pitch components; mounting a die-attach film on said thermal pads; curing said die-attach film; applying solvent to said die-attach film; forming component leads on said ultrafine pitch components; aligning said component leads to said solder pads; and mounting said ultrafine pitch components to said thermal pads.
Claim 9
Dependent Claim
36 words
The method of claim 6, wherein said method further includes: positioning said PC board in a solder dispensing machine; and heating said PC board in said solder dispensing machine; and applying flux to said solder pads.
Claim 10
Dependent Claim
24 words
The method of claim 6, wherein said curing said die-attach film consists of curing at 190 degrees Fahrenheit (88 degrees Celsius) for 5 minutes.
Claim 11
Dependent Claim
19 words
The method of claim 6, wherein said method further includes pressing said ultrafine pitch components with a heated thermode.
Claim 12
Independent Claim
187 words
A method of assembling coarse pitch components and ultrafine pitch components on a printed circuit (PC) board, said method comprising: providing a PC board having ultrafine pitch components with thermal pads and solder pads; paste printing a frontside of said PC board; dispensing glue on said frontside of said PC board; placing coarse pitch components on said frontside of said PC board; reflowing said frontside of said PC board; rating said paste printing, said dispensing, said placing, and said reflowing for a backside of said PC board; positioning said PC board in a solder dispensing machine; and heating said PC board in said solder dispensing machine; and applying flux to said solder pads; applying solvent to said thermal pads of said ultrafine pitch components; mounting a die-attach film on said thermal pads; curing said die-attach film at 190 degrees Fahrenheit (88 degrees Celsius) for 5 minutes; applying solvent to said die-attach film; forming component leads on said ultrafine pitch components; aligning said component leads to said solder pads; mounting said ultrafine pitch components to said thermal pads; and pressing said ultrafine pitch components with a heated thermode.
Claim 13
Independent Claim
187 words
A method of assembling coarse pitch components and ultrafine pitch components on a printed circuit (PC) board, said method comprising: providing a PC board having ultrafine pitch components with thermal pads and solder pads; paste printing a frontside of said PC board; dispensing glue on said frontside of said PC board; placing coarse pitch components on said frontside of said PC board; reflowing said frontside of said PC board; rating said paste printing, said dispensing, said placing, and said reflowing for a backside of said PC board; positioning said PC board in a solder dispensing machine; and heating said PC board in said solder dispensing machine; and applying flux to said solder pads; applying solvent to said thermal pads of said ultrafine pitch components; mounting a die-attach film on said thermal pads; curing said die-attach film at 190 degrees Fahrenheit (88 degrees Celsius) for 5 minutes; applying solvent to said die-attach film; forming component leads on said ultrafine pitch components; aligning said component leads to said solder pads; mounting said ultrafine pitch components to said thermal pads; and pressing said ultrafine pitch components with a heated thermode.
References Cited (Backward Citations)
US5480048A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-10-20 | 2001-04-21 | 2001-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-20 | 2005-04-21 | 2005-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-20 | 2009-04-21 | 2009-10-21 | $7700.00 | Window Closed / Lapsed |